Kormendy relation in the rest-frame B-band for cluster and field elliptical galaxies at z ≃ 1.3. Upper panel− the B-band surface brightness of the 17 galaxies in the cluster XMMU2235 at z ~ 1.39 (dark red filled squares), of the 16 galaxies in the RDCS0848 at z ~ 1.27 (brick red filled circles), and of the 23 galaxies in the cluster XLSS0223 at z ~ 1.22 (red filled triangles) are plotted as a function of their effective radius R_e at the redshift of the clusters. The three colored lines are the best fitting Kormendy relations to the three clusters reported in Table 1. The open symbols are the sample of early-type galaxies in the Linx clusters and groups studied by Raichoor et al. (2012). Lower panel: the surface brightness of the 56 cluster galaxies (red filled circles), of the 31 field galaxies at 1.2 <z< 1.45 in the GOODS-South region (blue filled squares), and of the 178 galaxies at 1.0 <z< 1.2 in the COSMOS area (green filled triangles) are plotted as a function of their effective radius. The red solid line and the blue dashed line are the best fitting relations obtained for cluster and GOODS-S field galaxies respectively, and are reported in Table 1. At the bottom of the figure, the mean age ⟨ age ⟩ [Gyr] of galaxies in the different intervals of effective radius together with its dispersion (σ) is reported.